1. Field
The present disclosure relates generally to digital imaging processing, and more particularly, to luma adaptation for digital image processing systems and processes.
2. Background
The demand for multimedia applications in mobile communications has been growing at an astounding rate. Today, a user can send and receive still images, as well as download images and video from the Internet, for viewing on a mobile terminal or handset. The integration of the digital camera into the mobile terminal has further contributed to the growing trend in mobile communications for multimedia functionality.
Given the limited amount of resources like battery capacity, processing power, and transmission speed associated with a mobile terminal, effective digital imaging processing techniques are needed to support multimedia functions. This requires the development of more sophisticated hardware and software that reduces computational complexity for multimedia applications while maintaining the image quality. The development of such hardware and software leads to lower power consumption and longer standby time for the mobile terminal.
One facet of the digital imaging process involves processing color information. Color information is generally represented as a composite signal consisting of red, green and blue (RGB) components. The data capacity required to convey this color information may be reduced by taking advantage of the relatively poor color acuity of the human eye, provided that the full luma bandwidth is maintained. In particular, the three color components (RGB) of the video signal may be transformed into luma (Y) and chroma (CbCr) components, and the chroma components compressed.
The luma (Y) component is generally associated with the brightness of the image. High dynamic range processing techniques are often employed in digital imaging processing systems to preserve the details of the image in the dark and light regions when the dynamic range of the scene is large. It would be desirable to achieve this with efficient processing resources suitable for mobile applications.
Luma adaptation is one type of high dynamic range image processing technique. It creates a non-linear tone reproduction curve which automatically varies according to the images' luminance distribution. The reproduction curve is generated based on the histogram information of images.